1. Field of the Invention
This invention relates to a wire harness that is capable of sufficiently maintaining air-tightness between an outer housing of a connector and a cable, and relates to a method of manufacturing the wire harness.
2. Description of the Related Art
Generally, in a wire harness used for vehicles etc., a connector part thereof is configured to have a water proof structure in order to prevent water or the like from entering into the inside of the connector so as to cause a problem, and an air-tightness maintaining structure for maintaining air-tightness between the outer housing of the connector and the cable is installed between them.
A conventional wire harness 41 shown in FIGS. 4A and 4B uses a wire seal 44 as the air-tightness maintaining structure.
The wire harness 41 is configured to maintain the air-tightness between the outer housing 43 of the connector 46 and the cable 42 by that a wire seal 44 formed of rubber for waterproofing is inserted between the outer housing 43 of the connector 46 and the cable 42, the wire seal 44 is crushed between the outer housing 43 and the cable 42 so that it is brought into close contact with both of the outer housing 43 and the cable 42.
In the outer housing 43, a cable insertion hole 47 into which an end portion of the cable 42 is inserted is formed, and the wire seal 44 is housed in a wire seal housing concave portion 48 formed in an insertion side of the cable insertion hole 47 of the outer housing 43. An opening part of the wire seal housing concave portion 48 is blocked with a tail plate 45 in order to prevent the wire seal 44 from dropping out.
However, in case of using the wire seal 44 for the air-tightness maintaining structure between the outer housing 43 and the cable 42, it is necessary to install the wire seal 44 corresponding to each of the cables 42 and house each of the wire seals 44 in the wire seal housing concave portion 48, so that a distance between the cables is broadened and it becomes difficult to shorten a pitch of the cable 42. In particular, the wire harness for vehicles is required to be downsized, so that there is a need for an air-tightness maintaining structure that is capable of further shortening the pitch of the cable 42.
Then, as shown in FIG. 5A, a wire harness 51 is proposed, that is configured to maintain the air-tightness between the outer housing 53 and the cable 52 by that the cable 52 is sandwiched between the outer housing 53 formed of a resin and a welding member 54 formed of a resin, the welding member 54 is welded to the outer housing 53 due to ultrasonic welding by using a horn 55 (for example, refer to JP-A-2000-48901).
As show in FIG. 5B, the wire harness 51 has a structure obtained by a method that grooves 53a are formed in the outer housing 53 and grooves 54a are formed in the welding member 54 respectively, cables 52 are disposed in the grooves 53a of the outer housing 53 and simultaneously the welding member 54 is stacked from above so as to locate the grooves 54a within positions of the cables 52, and in this condition, the horn 55 is brought into contact with an upper surface of the welding member 54 and is pressed from above down below while the welding member 54 is vibrated, and the welding member 54 is welded to the outer housing 53 due to the ultrasonic welding.
This technique is disclosed in, for example, JP-A-2000-48901 and JP-A-1999-66807.